Level.



H. R. MITCHELL & I. L. SLOAN.

LEVEL.

APPLICATION FILED APR.1, 1912.

' Patented Apr. 8, 1913.

Inventors Attorneys UNITED STATES PATENT OFFICE.

HARRY It. MITCHELL AND IRA I. SLOAN, OF SEATTLE, WASHINGTON.

LEVEL.

Specification of Letters Patent.

Application filed April 1, 1912. Serial No. 687,794.

To all whom it may concern:

Be it known that we, HARRY R. MI'iorinLL and IRA L. SLOAN, citizens ofthe United States, residing at Seattle, in the county of mounted plumbbob or weight actuated indicator or pointer is employed to visuallyindicate, while in co-active relation therewith is a switch connectedinan electrical circuit including an audible alarm, whereby the alarm isenergized to audibly indicate when the level is in the desiredhorizontal or perpendicular position. i f

A further object of the present invention is the provision of a foldinglevel, the central member of which forms a compartment for the receptionof a centrally disposed plumb bob indicator mechanism, a battery and anaudible alarm, a cut-oft switch being also disposed in the circuit andoperablecxteriorly of the level for placing the circuit into open orclosed condition.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being understood that changes in the preciseembodiment of the invention herein disclosed can be made within thescope of what is claimed without departing from the spirit of theinvention.

In the drawings-Figure l is a side elevation of the'central portion ofthe level, with the covers for the battery and alarm receptaclespartially removed, portions of the extensions being shown in extendedp0- Sl'tlOIl.

Fig. 2 is a top pla'rrview of the level, the extensions being shown indot-ted lines as folded. Fig. 3 is a section taken on line 3-3 ofFig. 1. Fig. 4 is a section taken on line 4-4 of Fig. 1. Fig. 5 is adiagrammatic view of the electrical circuit used in connection with thislevel.

Referring to the drawings, the numeral 1 designates the central or mainsection of the level while 2 and 2 designate the folding end sectionswhich are hingedly con- Patented Apr. 8, 1913.

nected with therespective ends of the main I section 1 by means of thehinge joints 3, the plates land 5 being disposed transversely of therespective ends of the section 1 and sections 2 and 2 and composed ofmeta-l. The plate 4 or 5 as clearly shown is provided with thetransverse groove 6, and in order to lock the extensions in extendedposition and permit the same to be folded to assume the dotted lineposition Fig. 2, the setscrews 7 are employed, the recesses 6 providinga means whereby the heads of said screws are positioned below the outersurface of the level and provide a connect-ion without any projectionbeyond the face of the level.

i The wall 8 and the transparent sheet 9.

constitute the front and rear walls of the indicator compartment of thelevel, while formed in the top and bottom of the level are the apertures10 and 10 respectively, which are closed by the strips 11 and 11 ofglass to permit the indicator to be observed.

The two journal lugs 12 and 13 carried by the respective walls 8 and 9provide a support for the arbor 14 which carries the in-- dicatingpointer 15 and the arm 16. The transversely disposed pin 17 forms apivotal connection with the lower end of the arm 16 and the weight ofplumb bob 19', the plumb bob being provided with'a recess 18 into whichthe lower end of the arm 16 projects as clearly shown in Fig. 1. By thismeans the visual indicator 15 is actuated to cooperate with the degreedial 20 to '-visually indicate the angle of indication of the pointer15.

Keyed upon and rotatable with the arbor 14 is a disk 21 made ofinsulation, the same having embedded therein and connected to the arbor14:, the four metal conducting the cut-away portion 25 which is of sucha contour as to correspond with the contour or periphery of the disk 21.A spring 26 mounted upon the pin 23 is so connected with relation to thearm 24 as to hold the with a battery '30 whichis disposed within'gagement with the contact 27 and thus energi'ze the circuit to actuatethe audible alarm,

toward either wall 8 01-9, an

curved portion thereof into sliding contact with the periphery of thedisk 21, so. that the contact gomt 27 carried by the-arm 24 will beplace into contact with the re- 5 spective outer ends of the conductors22, so

as to complete an electrical circuit, as will presentlyapfpear. Leadingtom the contact 27 IS a conductorplate 28- carried by the arm 24, and

connected to said contact plate 28 is a conductor 29 which is connected.at one side the battery compartment of the level. The conductor 31leads from the other side of the battery to theknifeswitch 32 which isso positioned in the level as to be readily acces'sible so thattheelectrical circuit may be connected or disconnected as desired. Leadingfromthe knife switch '32 isaconductor 33=which-isconnected to one postof the buzzer or audible alarm 34: mounted in the level on the oppositeside of the indicating compartment to the battery 30, the convductor 35leading from the other post of the audible alarm 34 being grounded withthrough the middle section of the level and arbor 14. L This circuit isclearly shown in dizigram in- Fig. 5. so 7 newed, the removable cover361s provided order that the battery may be refor the compartment of thelevel containing the battery and in order that the buzzer may. .be madeaccessible, the cover 37 is provided. I

From the foregoing description, taken in connection with the drawings,it is evident thatthe'level when placed in a horizontal plane and'theknife switch 32 is closed, that the plumb bob will rotate the arbor letto 40 assume the position as shown in Fig. .1, wherein one of. theconductors 22 are brought into electrical connection with the contactpoint 27,1;11115 establishing a circuit 1. to energize the buzzer so asto indicate audibl ,that' the surface is level. Should it be. esired. tolumb a perpendicular surface, the level Wlll be turned at right anglesto'the position shown in Fig. 1, so that the plumb bob will assume theposition to bring one of the conductors 22 into electrical en- By thisform of device, the level may be j operated 'inplaces where it isimpractical to use the ordinary form of, spirit leveland the veryinstant that the level is brought I to a horizontal or perpendicularlane, the electrical circuit will be closed and an audible alarm given.I r By reason ofv the pivoting of the plumb bob' or wei ht 19, with thearm .16 0f the indicator, t e actuation of the arbor willbe halted whenthe levelis out of use and lying upon its side, as the'wei ht will swingthusengage the level so that the circuit is completedarbor, a source 0electrical ener in a horizontal or vertical thesame to assume the dottedline position of Fig.-3, and thus act as a brake means to prevent thetwirlin of the arbor. By reason of the knife sw tch 32, the same may beoperated to open the circuit when the level is not in use and thus avoidthe possibility of the battery being wasted by contact at22 and 27.

.What is claimed is:

1. A level having a main portion provided with a receptacle, an arborcarrying an indicator' disposed therein, a weight connected at one endof the indicator, a source of electrical energy, a circuit connectedtherewith, an audible alarm in said circuit, a plurality of contactscarried by and rotatable with the arbor, and a contact disposed in thepath of the plurality of contacts to coact with either "one of saidcontacts to close the circuit when the level is in a horizontal orvertical position.

2.-A level having a main ortion provided with a receptacle,- an arborcarrying an indicator disposed therein, a weight connected to one end ofthe indicator, a source of electrical energy, a circuit connectedtherewith, an audible alarm in said circuit, a plurality of contactscarried by and rotatable with the arbor, a contact disposed in the pathof the plurality of contacts to coact with either one of said contactsto close the circuit when the level is in a horizontal or verticalposition, and a manually oper- "ated switch accessible from theexteriorof the level and connected insaid circuit.

3. A level, having a main section provided with a receptacle, an arbormounted in said receptacle, 9. visual indicator carried thereby, andoverbalancing means pivotally connected to the indicator, saidoverbala'ncing means being pivoted for swinging movement at right anglesto the movement of the arbor, a. source of electrical energy, a circuitincluding said source, an audible alarm in said circuit, andcoii'perable contacts in ing means being pivoted for swinging movementat right an les to the movement of the including said source, an'audib ealarm in said circuit, coiip'erable contacts in said circuit and carriedby the arbor and in the path thereof, anda manually operated switchaccessible exteriorly of the level, whereb when the switch is closed andthe level is position the electrical circuit will be closed.

, a circuit said disk of ms'ulation, and a coacting conpointing en tactin said circuitdisposed in the path to engage either one of the contactsof the disk to close the circuit when the level is in horizontal orvertical position.

6. A level, having a main section provided with a receptacle, an arborjournaled for rotation in said receptacle, an indicating pointer carriedthereby, an overbalancing means pivotally connected to the nonof thepointer and capable of a swinging movement at right angles to themovement of the arbor, a source of electri cal energy, a circuitincluding said source, an audible alarm in said circuit, a disk ofinsulation-connected to and rotatable with the arbor, a plurality ofcontacts carried by said disk of insulation, a coacting contact in saidcircuit disposed in the path to en age either one of the contacts of thedis to close the circuit when the level is in a horizontal or verticalposition, and a manually operated switch accessible from the exterior othe level connected in said circuit.

7. A level, having a rotating arbor, an indicator carried by the arbor,a circuit including a source of electrical energy, an audible alarm insaid circuit, a disk of insulation provided with a plurality of metalcontacts carried by the arbor and mounted in said circuit, and anothercontact in said' circuit disposed for coaction with one of the contactsat a time" to close the circuit when the level is in a horizontal orvertical position.

8. A level, having a rotating arbor, a

'visual'indicator carried by the arbor, a

circuit including a source of electrical energy, anaudlble alarm in saidc1rcu1t, a

disk of insulation provided with a plurality of metal contacts, carriedby the arbor and connected in said circuit, another contact in saidcircuit disposed for coaction with one of the contacts at a time toclose the circuit when the level is in a horizontal or verticalposition, and a manually operated switch acof the arbor carried contactsat a time to close the circuit when thelevel is in a horizontal orvertical position, and an overbalancing Weight for the visual indicatormounted to swing atright angles to the direction of rotation of thearbor.

In testimony that We claim the foregoing as our own, we have heretoaflixed our signatures in the presence of two witnesses.

' HARRY R. MITCHELL.

IRA L. SLOAN.

Witnesses as to signature of Harry R.

Mitchell:

, WM. MAXWELL,

' F. E. WHITE.

Witnesses as to signature of Ira L. Sloan:

JAMES O. GULL, RAY CAVALIN.

